If you think you have a cavity, the single most important thing to do is book a dental appointment. But what happens between now and that visit, and what to expect once you’re in the chair, depends on how far the decay has progressed. A cavity caught early can sometimes be reversed without drilling. One that’s been growing for months may need a filling, a crown, or more involved treatment. Here’s what to know at every stage.
Not All Cavities Need Drilling
Tooth decay isn’t an on/off switch. It starts as a process called demineralization: bacteria in your mouth feed on sugars and produce acid, which drops the pH below about 5.5 and dissolves minerals from your enamel. At this earliest stage, you might notice a white or chalky spot on a tooth but no actual hole. That spot is weakened enamel, not yet a full cavity.
The good news is your saliva naturally repairs enamel by depositing calcium and phosphate back into the tooth surface. Fluoride supercharges this process. When fluoride is present in your saliva, even in very low concentrations, the repaired enamel incorporates a stronger mineral that resists future acid attacks better than the original surface did. This is why fluoride toothpaste, prescription fluoride rinses, or professional fluoride treatments can genuinely reverse early decay before it becomes a cavity that needs a filling.
Your dentist can tell you whether a spot of decay is still in this reversible window. If it is, the plan is usually straightforward: consistent fluoride use, better brushing and flossing habits, and reducing how often you snack on sugary or acidic foods throughout the day. Frequency matters more than quantity here. Sipping a soda over two hours does more damage than drinking it in five minutes, because your mouth stays acidic longer.
Managing Pain Before Your Appointment
If the cavity is causing discomfort, over-the-counter pain relievers like ibuprofen or acetaminophen can help while you wait for your visit. Don’t place aspirin directly on your gum near the sore tooth, as it can burn the tissue. Topical numbing gels containing benzocaine offer short-term relief, but use them sparingly and follow the dosing instructions on the package. Products with benzocaine should not be used on children under two.
Rinsing gently with warm salt water can reduce inflammation and help keep the area clean. Avoid very hot, very cold, or sugary foods and drinks that tend to trigger sharp pain in a tooth with active decay. These steps buy you time, but they aren’t treatment. The underlying decay will keep progressing until a dentist addresses it.
What Happens During a Filling
For most cavities, a filling is the standard fix. The process is quicker and less dramatic than many people expect. Your dentist numbs the tooth and surrounding area with a local anesthetic, then uses specialized instruments to remove the decayed portion of the tooth. Once the decay is cleared, the resulting hole is filled with a restorative material, shaped to match your bite, and polished smooth. For composite (tooth-colored) fillings, a curing light hardens the material in seconds. The whole procedure typically takes 20 to 60 minutes depending on the size and location of the cavity.
You’ll likely feel numbness for an hour or two afterward. Some sensitivity to hot and cold is normal for a few days to a couple of weeks. If it lingers beyond that, or if your bite feels off, call your dentist for an adjustment.
Filling Materials
The two most common options are composite resin (tooth-colored) and amalgam (silver-colored). Composite has become the more popular choice, partly for cosmetic reasons and partly because large-scale data shows it performs well. In one analysis covering eight years, composite fillings had a failure rate of about 12%, compared to roughly 17% for amalgam over the same period. Both can last many years with good oral hygiene. Your dentist will recommend one based on the tooth’s location, the size of the cavity, and your preference.
When a Filling Isn’t Enough
If decay has destroyed a large portion of the tooth, a simple filling may not provide enough structural support. In these cases, a crown, which is essentially a custom-fitted cap that covers the entire visible portion of the tooth, is the better option. Crowns are especially common for molars and premolars, which absorb the full force of chewing and grinding. They’re also typical for teeth that have already undergone multiple restorations.
Crowns cost significantly more than fillings. Without insurance, expect to pay between $800 and $2,500 per crown depending on the material. Ceramic and zirconia crowns average around $1,300, while porcelain fused to metal tends to be slightly less. Insurance often covers a portion, but you’ll want to verify your plan’s specifics before the procedure.
If the decay has reached the innermost part of the tooth, the pulp, where nerves and blood vessels live, you’re in root canal territory. This means bacteria have penetrated deep enough to cause infection or inflammation inside the tooth. A root canal removes the infected pulp, cleans the interior, and seals it. Back teeth that undergo root canals usually need a crown afterward for reinforcement, while front teeth sometimes do fine with just a filling, since they bear less chewing force.
What Happens If You Wait Too Long
Ignoring a cavity doesn’t make it go away. Decay moves inward through the enamel, then into the softer layer beneath it called dentin, and eventually into the pulp. Once bacteria reach the pulp, they can travel down to the tip of the root and form a pocket of infection called an abscess. Symptoms at this stage can include throbbing pain, swelling in the jaw or face, fever, and a foul taste from draining pus.
An abscess won’t resolve on its own. If it doesn’t drain, the infection can spread into the jawbone, other areas of the head and neck, or even into the sinus cavity if the tooth sits near the sinuses behind your cheekbones. In rare but serious cases, an untreated dental infection can lead to sepsis, a body-wide infection that requires emergency medical care. What starts as a small, inexpensive filling can become a root canal, an extraction, or a hospital visit if left untreated long enough.
Cavities in Children’s Baby Teeth
A common question parents have is whether a cavity in a baby tooth even matters, since the tooth will fall out eventually. In most cases, yes, it still needs treatment. Baby teeth hold space for permanent teeth and help with speech development and chewing. Untreated decay can cause pain, infection, and damage to the developing permanent tooth underneath.
The treatment approach depends on the child’s age, the tooth’s location, and how severe the decay is. Mild to moderate cavities in baby teeth are typically filled, just like adult teeth. If the tooth is already loose and close to falling out naturally, extraction may make more sense. Your child’s dentist will weigh these factors and recommend the most practical option.
A Non-Drilling Option Worth Knowing About
Silver diamine fluoride, often called SDF, is a liquid applied directly to a cavity that can stop decay from progressing without any drilling. It’s painted on in under a minute and works by killing bacteria and hardening the remaining tooth structure. For preventing and arresting root cavities in adults, studies show success rates significantly higher than placebo treatments.
The main drawback is cosmetic: SDF permanently stains the decayed area black. This makes it less appealing for visible front teeth but a practical choice for back teeth, baby teeth, or situations where a patient can’t tolerate traditional dental work, such as very young children, elderly patients, or people with dental anxiety. It doesn’t restore the tooth’s shape, so it’s not a replacement for a filling in every situation, but it can be a valuable tool for stopping decay in its tracks.